DE2256540C3 - Electronic wrist watch with a stepping motor and a time display corrector - Google Patents

Description

The invention relates to an electronic wristwatch with the features of the preamble of Claim 1.

Quartz crystal controlled wristwatches are characterized by a very high level of accuracy, you monthly error is within ± 5 seconds. The time display of such a watch is therefore rarely wrong. Still, the wearers of such watches are worried if for a long time a false report occurs in the order of a few seconds, and they are eager to find a to correct such a mistake. For the purpose of correcting the time display, but especially for the Purpose of readjusting the time display after a repair, a battery change or the like. It is at Clocks with digital time display known to provide facilities with which the time display on a A certain value, for example 0, can be reset or set to other values in a targeted manner. This usually requires several switches. So much for resetting counter circuits pulse-shaped signal is required, it is known to generate such a signal by closing a switch with the aid of a to form downstream monoflop circuit (DE-OS 15 48 081).

There are clocks with hand time display are known whose timing signal is electronic generated and translated into rotary motion with the help of an electromechanical transducer (DE-OS 19 52 203). A watch of the type mentioned with an electro-mechanical converter in DE-OS 17 73 675 shows training as a stepper motor. The converter used for this works with an armature moving back and forth, which has a pawl and a ratchet wheel converts its movement into a rotary movement. But it is already a stepper motor known, in which a reciprocating mechanical intermediate part is omitted and with a of the alternating signals accordingly alternately magnetically controlled stator and one has this associated rotor, which has magnetic poles in sequence over its circumference has alternating polarity (DE-OS 19 55 698). An electrical display corrector is in the Connection with these known pointer watches is not disclosed

If such a known wristwatch with a mechanical time display goes behind for a small error, then it must the clock must first be stopped, then the time display is advanced accordingly and finally the The clock is restarted at the set time. Such handling otherwise leaves them alone Due to their high accuracy, watches of the aforementioned type are complicated and excellent seem cumbersome to use.

It is the object of the invention to create a watch of the type mentioned, the seconds display in can be corrected quickly in a simple manner in terms of design and operation.

The object is achieved by the subject matter of claim 1.

The low operating frequency of the stepper motor in connection with the possibility of rapid pulse delivery of the switch allow the time display to be corrected quickly and conveniently, as it is done quickly Switch actuation a correspondingly large correction step is possible. With just one switch by using the counter provided for normal operation, a continuation signal age- The changing direction of the current is made available, whereby a slowing of the clock can be corrected The same switch can be used to proceed the clock by stopping the stepper motor via a corresponding Correct over time. With this quick correction option, a possibly occurring Eliminate errors in the time display very quickly, thereby reducing the utility value of the watch unimpaired rate accuracy is increased. The handling with the help of only one switch comes to that Opposite to ease of use, in addition, possible sources of error and the constructive Effort reduced to a minimum.

In a particularly preferred embodiment, the switch is designed as a closing contact. Also preferred a capacitor is connected in parallel to the switch to largely reduce the operating time of the switch becoming independent and generating a signal that is specific in terms of its pulse duration is in further preferred training the switch is followed by a monostable multivibrator, its The output is fed to one coil connection of the drive coil of the stepping motor via a gate circuit is, the switch is led in parallel to a certain input of the counter, which is controlled in this way is that when the switch is released at the corresponding counter output, a signal pulse is reversed Stromrichtiing and again with a predetermined duration is supplied to the other coil connection.

Further explanations result from the subclaims.

The following description uses the exemplary embodiment shown in the drawing the invention explained in more detail. It shows

F i g. 1 is a block circuit diagram of the embodiment,

F i g. 2 shows a time diagram of the voltage or current ratios at various points in the Block diagram according to FIG. 1 with normal operation of the clock and with the application of correction signals.

An inverter / j for an oscillator is assigned to an oscillating crystal X-tal and transmits the stable output signal! of the oscillating crystal to a subsequent counter and pulse shaping circuit C. The shaped output signal of this circuit C is amplified with the aid of a NOR gate NRi and further inverters / 2, / 3 and / 4 and drives a corresponding current through a drive coil L of the stepping motor.

F i g. 2 shows an example of a timing diagram for the Course of voltages and currents at some circuit points in the event that the input frequency 16384 kHz and a 15-digit binary counter is used.

Then, during normal operation, a pulsed current is passed through the coil L , which inverts every 1 second, as shown in the left half of FIG. 2 is shown. As a result, magnetic north and south poles are alternately impressed on the stator S of the electro-mechanical converter. The stator 5 is assigned a rotor Ro which has six magnetic coils of alternating polarity with regard to its circumference, as can be seen from FIG. 1. The rotor Ro is accordingly rotated by 60 ° every second and drives a pinion 4 with a corresponding reduction, which carries a second hand.

The following describes the rapid movement and the rapid feeding of control signals for the seconds display. With the help of a NOR gate NR ₂ , an inverter / 5, and an ftC element that determines the time constant, a monostable multivibrator is formed, as shown in FIG. 1 shows. One connection of the gate NR2, to which trigger pulses are supplied, is simultaneously with a setting or setting. Continuation terminal PR of the circuit C containing a counter connected. The counter is incremented as often as a trigger occurs

If a correction switch SW is switched on to advance the second hand, an output voltage appears immediately at the output OUTi of the monostable multivibrator, and a current is fed to the electro-mechanical converter in the same direction as it is at the output OUT _{2 of} the circuit C occurs The counter of circuit C is incremented at the same time in such a way that an output voltage appears at the output OUTj as soon as the switch SW is switched off again, as a result of which a current which is opposite to the aforementioned current flows through the drive coil L. If, for example, switching the correction switch on and off is repeated, the rotor of the electro-mechanical converter rotates by 120 °, which corresponds to a time display of 2 seconds. If, on the other hand, a stop is desired, the switch S WIn is held in the closed position.

It should be noted that in the example chosen according to FIG. 2, the pulse width for controlling the current through the coil is L = V _M see.

With the correction switch, the correction of the seconds display is made easy, which was not possible with the known quartz crystal wristwatches. In this way, the practical value of such watches increases. In order to make the pulse width of the monostable multivibrator approximately the same as that at the output OUT2 and to prevent the outputs OUT ₁ and OLT _{3 from} overlapping, a capacitor is connected in parallel to the switch. With a few exceptions, in particular capacitors, the aforementioned circuit elements can be combined in complementary field effect transistor technology, which proves to be advantageous with regard to the energy required. If the circuit is implemented, at least to a considerable extent, in monolithic integrated circuit technology, then one makes a considerable contribution to the compact design of a quartz crystal wristwatch.

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1.Electronic wristwatch with an oscillating crystal as the time standard, a counter and pulse shaper circuit, especially executed in integrated complementary field effect transistor circuit technology, and a stepper motor as an electro-mechanical converter, to which the output signal of the counter and pulse shaper circuit is alternating in terms of the current direction A drive signal of a few Hertz or less is supplied and which drives a pointer mechanism, characterized in that a switch (SW) is provided with which an additional alternating drive signal is supplied to the stepper motor (L, S, Ro) by briefly actuating it Part with one polarity is fed to the output of the counter circuit (C) and its part with the other polarity is generated by incrementing the counter, and with which switch the stepper motor can be stopped by correspondingly continuous actuation. 2. Clock according to claim 1, characterized in that the switch (SW) is designed as a make contact. 3. Clock according to claim 1 or 2, characterized in that the switch (SW) a capacitor is connected in parallel 4. Clock according to one of the preceding claims, characterized in that the switch (SW) is followed by a monostable Miltivibrator (NR ₂ , h, C, R) , the output of which is the one coil connection of the drive coil (L) of the stepping motor (LS, Ro ) is supplied via a Galter circuit (NR _U U).